Artificial moral agents – systems that engage in explicit moral reasoning on their own and with users – present a potential new paradigm for behavior and system change for social and environmental sustainability. Moral agents could replace current individualist, prescriptive, inflexible, and opaque interventions with systems that transparently state their values and then openly deliberate and contest these with users, or agents that represent human and non-human stakeholders such as future generations, species, or ecosystems. Indeed, moral agents could mark a genuine new form of more-than-human interactions and human-technology relation, where we relate to artificial systems as a counterpart. To jointly articulate key questions and possible futures around moral agents, this workshop convenes HCI, AI, behaviour change, and critical and speculative design researchers and practitioners.